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Updated: May 23, 2025

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
A highly selective C-H bond fluorination unlocks conformational reporting in a complex natural product derivative
Jonah Ruskin1, Roxanne Dekeyser2, Nathaniel Garrison1
1Department of Chemistry, Johns Hopkins University 3400 North Charles St. Baltimore MD 21218 USA lectka@jhu.edu.
Abstract:
The site-selective C-H bond fluorination of complex natural products is one of the more sought-after transformations in organic and medicinal chemistry. In many radical-based fluorinations, however, a tempest of poor regio- and stereoselectivity, multiple additions of fluorine, and difficult separations of products conspire to make selective monofluorination appear out of reach. In our fluorination of the antibiotic ionophore salinomycin and its simple derivatives, however, a chain of discoveries, including an unanticipated skeletal rearrangement, provided us a tortuous but unique path to a very selective result, unlocking low-noise conformational reporting by 19F NMR in a widely studied medicinal scaffold.
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